@interfaceHYShowImageView:UIScrollView<UIScrollViewDelegate>//显示图像大图-(void)showImage:(UIImage*)image
@interface HYShowImageView : UIScrollView <UIScrollViewDelegate>//显示图像大图-(void)showImage:(UIImage*)image inView:(UIView *)parentsView fromRect:(CGRect)rect;@end
先看一下头文件，继承UIScrollView，实现UIScrollViewDelegate协议。
提供了一个方法ShowImage。
接下来看看这个方法是实现
-(void)showImage:(UIImage*)image inView:(UIView *)parentsView fromRect:(CGRect)rect{ _oldRect = rect; [self setFrame:CGRectMake(0, 0, PHOTOWIDTH, PHOTOHEIGHT)]; self.showsHorizontalScrollIndicator = NO; self.showsVerticalScrollIndicator = NO; UIImageView *showView = [[UIImageView alloc] initWithFrame:_oldRect]; showView.contentMode = UIViewContentModeScaleAspectFit; [UIView animateWithDuration:0.5f animations:^{ [showView setFrame:CGRectMake(0, 0, PHOTOWIDTH, PHOTOHEIGHT)]; }]; [self setBackgroundColor:color_with_rgba(0, 0, 0, 1)]; [parentsView addSubview:self]; [showView setTag:'show']; [showView setImage:image]; //这个地方也可以用网络的图片 [self addSubview:showView]; //增加两个手势 showView.userInteractionEnabled = YES; UITapGestureRecognizer* singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleViewTap:)]; [self addGestureRecognizer:singleTap]; UIPinchGestureRecognizer* pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinchView:)]; [self addGestureRecognizer:pinchGesture];}
增加了两个手势，一个点击取消，一个缩放
//移除图片查看视图-(void)handleSingleViewTap:(UITapGestureRecognizer *)sender{ [self setZoomScale:1.0 animated:NO]; [UIView animateWithDuration:0.5f animations:^{ UIImageView *showView = (UIImageView *)[self viewWithTag:'show']; showView.frame = _oldRect; self.backgroundColor = color_with_rgba(0, 0, 0, 0.0); } completion:^(BOOL finished){ [self removeFromSuperview]; }];}
//缩放图片-(void)handlePinchView:(UIPinchGestureRecognizer *)sender{ UIImageView *imageView = (UIImageView *)[self viewWithTag:'show']; if ([sender state] == UIGestureRecognizerStateBegan) { _imageHWScale = imageView.image.size.height/imageView.image.size.width; _beganScale = self.zoomScale; } [self setZoomScale:_beganScale * sender.scale]; if ([sender state] == UIGestureRecognizerStateEnded) { [self scrollViewEnd]; }}- (void)scrollViewEnd{ if (self.zoomScale < 1.0) { [self setZoomScale:1.0 animated:YES]; self.contentOffset = CGPointMake(0, 0); } else if (self.zoomScale > 3.0) { [self setZoomScale:3.0 animated:YES]; }}
实现委托的方法：
#pragma mark - ScrollView delegate-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{ for (UIView *v in scrollView.subviews){ return v; } return nil;}- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale{ [self scrollViewEnd];}·- (void)scrollViewDidZoom:(UIScrollView *)scrollView{ UIImageView *imageView = (UIImageView *)[self viewWithTag:'show']; _imageHWScale = imageView.image.size.height/imageView.image.size.width; if (self.contentOffset.x<=0 && self.contentOffset.y<=0) { self.contentOffset = CGPointMake((imageView.width - PHOTOWIDTH)/2, (imageView.width - PHOTOWIDTH)); }}
总结：
优点：这种缩放方式是使用了ScrollView自带的zoom缩放，所有使用简单
缺点：这种缩放方式如果图片高度不符合屏幕的话，放大后上下会有很大的空白部分（待解决）
推荐使用库：MJPhotoBrowse:http://code4app.com/ios/快速集成图片浏览器/525e06116803fa7b0a000001
原版本有一些问题，我修改了bug到了这里:http://git.oschina.net/jonear/MJPhotoBrowser
